SQLite Archiver

Without a FILES argument, all files are extracted.

All commands can be supplemented with -v for verbose output. For example:

        sar -v ARCHIVE FILES..
        sar -lv ARCHIVE
        sar -xv ARCHIVE

File are normally compressed using zlib prior to being stored as BLOBs in
the database.  However, if the file is incompressible or if the -n option
is used on the command-line, then the file is stored in the database exactly
as it appears on disk, without compression.
    
## Storage

The database schema looks like this:

        CREATE TABLE sar(
          name TEXT PRIMARY KEY,  -- name of the file
          mode INT,               -- access permissions
          mtime INT,              -- last modification time
          sz INT,                 -- original file size
          data BLOB               -- compressed content
        );
        
Both directories and empty files have sar.sz==0.  Directories can be
distinguished from empty file because directories have sar.data IS NULL.
The sar.data file is compressed if length(sar.blob)<sar.sz and is stored
as plaintext if length(sar.blob)==sar.sz.

/*
** Show a help message and quit.
*/
static void showHelp(const char *argv0){
  fprintf(stderr, "Usage: %s [options] archive [files...]\n", argv0);
  fprintf(stderr, "Options:\n"
                  "   -l      List files in archive\n"
                  "   -n      Do not compress files\n"
                  "   -x      Extract files from archive\n"
                  "   -v      Verbose output\n"
  );
  exit(1);
}

/*

    errorMsg("Error: %s\nwhile preparing: %s\n",
             sqlite3_errmsg(db), zSql);
  }
}

/*
** Read a file from disk into memory obtained from sqlite3_malloc().
** Compress the file as it is read in if doing so reduces the file
** size and if the noCompress flag is false.
**
** Return the original size and the compressed size of the file in
** *pSizeOrig and *pSizeCompr, respectively.  If these two values are
** equal, that means the file was not compressed.
*/
static char *read_file(
  const char *zFilename,    /* Name of file to read */
  int *pSizeOrig,           /* Write original file size here */
  int *pSizeCompr,          /* Write compressed file size here */
  int noCompress            /* Do not compress if true */
){
  FILE *in;
  char *zIn;
  long int nIn;
  char *zCompr;
  unsigned long int nCompr;
  int rc;

  in = fopen(zFilename, "rb");
  if( in==0 ) errorMsg("cannot open \"%s\" for reading\n", zFilename);
  fseek(in, 0, SEEK_END);
  nIn = ftell(in);
  rewind(in);
  zIn = sqlite3_malloc( nIn+1 );
  if( zIn==0 ) errorMsg("cannot malloc for %d bytes\n", nIn+1);
  if( nIn>0 && fread(zIn, nIn, 1, in)!=1 ){
    errorMsg("unable to read %d bytes of file %s\n", nIn, zFilename);
  }
  fclose(in);
  if( noCompress ){
    *pSizeOrig = *pSizeCompr = nIn;
    return zIn;
  }
  nCompr = 13 + nIn + (nIn+999)/1000;
  zCompr = sqlite3_malloc( nCompr+1 );
  if( zCompr==0 ) errorMsg("cannot malloc for %d bytes\n", nCompr+1);
  rc = compress(zCompr, &nCompr, zIn, nIn);
  if( rc!=Z_OK ) errorMsg("Cannot compress %s\n", zFilename);
  if( nIn>nCompr ){
    sqlite3_free(zIn);
    *pSizeOrig = nIn;
    *pSizeCompr = (int)nCompr;
    return zCompr;
  }else{
    sqlite3_free(zCompr);
    *pSizeOrig = *pSizeCompr = nIn;
    return zIn;
  }
}

/*
** Make sure the parent directory for zName exists.  Create it if it does
** not exist.
*/
static void make_parent_directory(const char *zName){

/*
** Write a file or a directory.
**
** Create any missing directories leading up to the given file or directory.
** Also set the access mode and the modification time.
**
** If sz>nCompr that means that the content is compressed and needs to be
** decompressed before writing.
*/
static void write_file(
  const char *zFilename,   /* Store content in this file */
  int iMode,               /* The unix-style access mode */
  sqlite3_int64 mtime,     /* Modification time */
  int sz,                  /* Size of file as stored on disk */
  const char *pCompr,      /* Content (usually compressed) */
  int nCompr               /* Size of content (prior to decompression) */
){
  char *pOut;
  unsigned long int nOut;
  int rc;
  FILE *out;
  make_parent_directory(zFilename);
  if( pCompr==0 ){
    rc = mkdir(zFilename, iMode);
    if( rc ) errorMsg("cannot make directory: %s\n", zFilename);
    return;
  }
  out = fopen(zFilename, "wb");
  if( out==0 ) errorMsg("cannot open for writing: %s\n", zFilename);
  if( sz==nCompr ){
    if( sz>0 && fwrite(pCompr, sz, 1, out)!=1 ){
      errorMsg("failed to write: %s\n", zFilename);
    }
  }else{
    pOut = sqlite3_malloc( sz+1 );
    if( pOut==0 ) errorMsg("cannot allocate %d bytes\n", sz+1);
    nOut = sz;
    rc = uncompress(pOut, &nOut, pCompr, nCompr);
    if( rc!=Z_OK ) errorMsg("uncompress failed for %s\n", zFilename);


    if( nOut>0 && fwrite(pOut, nOut, 1, out)!=1 ){
      errorMsg("failed to write: %s\n", zFilename);
    }
    sqlite3_free(pOut);
  }
  fclose(out);
  rc = chmod(zFilename, iMode&0777);
  if( rc ) errorMsg("cannot change mode to %03o: %s\n", iMode, zFilename);

}

/*
** Error out if there are any issues with the given filename
*/
static void check_filename(const char *z){
  if( strncmp(z, "../", 3)==0 || sqlite3_strglob("*/../*", z)==0 ){
    errorMsg("Filename with '..' in its path: %s\n", z);
  }
  if( sqlite3_strglob("*\\*", z)==0 ){
    errorMsg("Filename with '\\' in its name: %s\n", z);
  }
}

/*
** Add a file to the database.
*/
static void add_file(
  const char *zFilename,     /* Name of file to add */
  int verboseFlag,           /* If true, show each file added */
  int noCompress             /* If true, always omit compression */
){
  int rc;
  struct stat x;
  char *zContent;
  int szOrig;
  int szCompr;
  const char *zName;

  }
  zName = zFilename;
  while( zName[0]=='/' ) zName++;
  sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
  sqlite3_bind_int(pStmt, 2, x.st_mode);
  sqlite3_bind_int64(pStmt, 3, x.st_mtime);
  if( S_ISREG(x.st_mode) ){
    char *zContent = read_file(zFilename, &szOrig, &szCompr, noCompress);
    sqlite3_bind_int(pStmt, 4, szOrig);
    sqlite3_bind_blob(pStmt, 5, zContent, szCompr, sqlite3_free);
    if( verboseFlag ){
      if( szCompr<szOrig ){
        int pct = szOrig ? (100*(sqlite3_int64)szCompr)/szOrig : 0;
        printf("  added: %s (deflate %d%%)\n", zFilename, 100-pct);
      }else{
        printf("  added: %s\n", zFilename);
      }
    } 
  }else{
    sqlite3_bind_int(pStmt, 4, 0);
    sqlite3_bind_null(pStmt, 5);
    if( verboseFlag ) printf("  added: %s\n", zFilename);
  }
  rc = sqlite3_step(pStmt);

    d = opendir(zFilename);
    if( d ){
      while( (pEntry = readdir(d))!=0 ){
        if( strcmp(pEntry->d_name,".")==0 || strcmp(pEntry->d_name,"..")==0 ){
          continue;
        }
        char *zSubpath = sqlite3_mprintf("%s/%s", zFilename, pEntry->d_name);
        add_file(zSubpath, verboseFlag, noCompress);
        sqlite3_free(zSubpath);
      }
    }
  }
}

/*

int main(int argc, char **argv){
  const char *zArchive = 0;
  char **azFiles = 0;
  int nFiles = 0;
  int listFlag = 0;
  int extractFlag = 0;
  int verboseFlag = 0;
  int noCompress = 0;
  int i, j;

  if( sqlite3_strglob("*/unsar", argv[0])==0 ){
    extractFlag = 1;
  }
  for(i=1; i<argc; i++){
    if( argv[i][0]=='-' ){
      for(j=1; argv[i][j]; j++){
        switch( argv[i][j] ){
          case 'l':   listFlag = 1;    break;
          case 'n':   noCompress = 1;  break;
          case 'v':   verboseFlag = 1; break;
          case 'x':   extractFlag = 1; break;
          case '-':   break;
          default:    showHelp(argv[0]);
        }
      }
    }else if( zArchive==0 ){

                 sqlite3_column_bytes(pStmt,4));
    }
    db_close(1);
  }else{
    if( azFiles==0 ) showHelp(argv[0]);
    db_open(zArchive, 1);
    for(i=0; i<nFiles; i++){
      add_file(azFiles[i], verboseFlag, noCompress);
    }
    db_close(1);
  }
  return 0;
}